1. Field of the Invention
The present invention relates generally to multi-fiber (MF) ferrules used to connect optical fibers and devices within optical communications networks. More specifically, the present invention relates to angle-specific, lateral offset-optimized MF ferrules and associated methods of manufacture.
2. Technical Background of the Invention
A conventional MF ferrule includes two guide pin holes or bores and a plurality of optical fiber holes or bores that are disposed substantially between the two guide pin holes. Two MF ferrules are assembled together and optically coupled using two guide pins that are disposed in the two guide pin holes of each of the MF ferrules, aligning the plurality of optical fiber holes and corresponding plurality of optical fibers. The same mechanism is often used to assemble together and optically couple an MF ferrule and a device. The alignment of each of the optical fiber holes from one MF ferrule to another, or from one MF ferrule to a device, is critical in order to achieve low insertion or connectivity loss. The farther the plurality of optical fiber holes are from their desired target locations, due to manufacturing tolerances, for example, the higher the insertion loss. In general, a 1.3 μm radial offset for one MF ferrule is considered to be acceptable. This is true for MF ferrules with both flat and pre-angled (8-degree) endfaces.
As of yet, there is an unresolved need for methods of manufacture that minimize the lateral offset of the plurality of optical fiber holes associated with MF ferrules. This problem is exacerbated by the fact that, as optical fiber and ferrule materials are removed from the endface of an MF ferrule, such as during polishing, for example, this lateral offset often changes, both in degree and potentially direction, becoming more or less pronounced in an unpredictable manner. This is caused by the fact that, due to manufacturing tolerances, for example, each of the optical fiber holes may be angled with respect to the endface of the MF ferrule. The methods of manufacture that minimize the lateral offset of the plurality of optical fiber holes associated with the MF ferrule should take advantage of this lateral offset change.